1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <compositionengine/impl/HwcBufferCache.h>
18 #include <gui/BufferQueue.h>
19 #include <ui/GraphicBuffer.h>
20
21 namespace android::compositionengine::impl {
22
HwcBufferCache()23 HwcBufferCache::HwcBufferCache() {
24 std::fill(std::begin(mBuffers), std::end(mBuffers), wp<GraphicBuffer>(nullptr));
25 }
26
getHwcBuffer(int slot,const sp<GraphicBuffer> & buffer,uint32_t * outSlot,sp<GraphicBuffer> * outBuffer)27 void HwcBufferCache::getHwcBuffer(int slot, const sp<GraphicBuffer>& buffer, uint32_t* outSlot,
28 sp<GraphicBuffer>* outBuffer) {
29 // default is 0
30 if (slot == BufferQueue::INVALID_BUFFER_SLOT || slot < 0 ||
31 slot >= BufferQueue::NUM_BUFFER_SLOTS) {
32 *outSlot = 0;
33 } else {
34 *outSlot = slot;
35 }
36
37 auto& currentBuffer = mBuffers[*outSlot];
38 wp<GraphicBuffer> weakCopy(buffer);
39 if (currentBuffer == weakCopy) {
40 // already cached in HWC, skip sending the buffer
41 *outBuffer = nullptr;
42 } else {
43 *outBuffer = buffer;
44
45 // update cache
46 currentBuffer = buffer;
47 }
48 }
49
50 } // namespace android::compositionengine::impl
51